How to know my 30 day active users count??

[AgeofIron1990]

Hi all, I am hoping to start some re-marketing list campaigns on YouTube but not sure where to look to find my 30 day active users count? Is this synonymous with impressions? Additionally I would love any advice on how to get this number up--other than the obvious "upload more/better content"--would it be wise to use non re-marketed YouTube ads to try and increase my active users in order to be eligible for re-marketing?

Any and all advice is appreciated!!